The present invention relates generally to a method of reverse engineering of printed wiring boards and, more particularly, to the cloning of printed wiring boards to produce an exact replica of the original.
The state of the art of circuit reverse engineering is well represented and alleviated to some degree by the prior art apparatus and approaches which are contained in the following U.S. patents:
U.S. Pat. No. 3,564,358 issued to Hahnlein on Feb. 16, 1971;
U.S. Pat. No. 3,430,564 issued to Silvia et al on Mar. 4, 1969;
U.S. Pat. No. 3,721,838 issued to Brickman et al on Mar. 20, 1973; and
U.S. Pat. No. 4,766,516 issued to Ozdemir et al on Aug. 23, 1988.
The Hahnlein patent discloses an integrated circuit structure having several silicon layers electrically isolated and capacitively decoupled from each succeeding layer by means of intermediate insulting layers of aluminum silicates, said layers being successively deposited on a silicon substrate.
The Silvia et al patent discloses an all secondary explosive, logic and switching device in which a point contact from an explosive trail with a constricted region of the same or other explosive trail can produce a destructive cross-over, an explosive gate, diode and switch or other logic operation.
The Brickman et al patent is directed to an electrically alterable bistable element, typically an amorphous chalcogenide or amorphous metal-oxide, is connected in the circuit of a monolithic device and adapted to be electrically programmed for substitution of a circuit element or groups of circuit elements for other elements. The ability of a monolithic device to be repaired increases yields in manufacturing, lowers cost and extends the lifetime of such devices.
The Ozdemir et al patent discusses the method and apparatus for securing integrated circuits from unauthorized copying and use wherein at least one additional circuit element that does not contribute toward the integrated circuit's circuit function, but inhibits proper functioning of the integrated circuit in case of an attempted copying or other unauthorized use. The identity of the additional circuit elements is disguised by forming the with the visible appearance of an apparent element but with a physical modification which is not readily visible but causes them to function in a different manner, by providing different ICs with unique control codes, or both. Physical modifications not readily visible to a copyist include very narrow open circuit cuts in metalized connection lines, preferably with a focused ion beam or laser beam; and/or disordering the lattice structure or changing the doping level of a semiconductor region, and/or injecting electrical charge into a semiconductor region, preferably with an electron beam. The additional elements can be formed into a control code subcircuit for the IC, with the code disguised by the use of apparent elements.
Many older boards are lacking data for reproducing during surge requirements. In many cases the companies that produced the boards originally are no longer in business. The only alternative is to reverse engineer the boards at great cost in time and manpower. There was a critical need to find a fast, cost-effective way to reproduce the needed data to build new boards.
While the above-cited references are instructive, there still remains a need to provide a method of cloning printed wiring boards to produce an exact replica of the original board. The present invention is intended to satisfy that need.